644430366 has 24 divisors (see below), whose sum is σ = 1396862064. Its totient is φ = 214718400.

The previous prime is 644430359. The next prime is 644430383. The reversal of 644430366 is 663034446.

644430366 is a `hidden beast` number, since 644 + 4 + 3 + 0 + 3 + 6 + 6 = 666.

644430366 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 644430366.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 45766 + ... + 58166.

It is an arithmetic number, because the mean of its divisors is an integer number (58202586).

Almost surely, 2^644430366 is an apocalyptic number.

644430366 is an abundant number, since it is smaller than the sum of its proper divisors (752431698).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644430366 is a wasteful number, since it uses less digits than its factorization.

644430366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15296 (or 15293 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 36.

The square root of 644430366 is about 25385.6330628172. The cubic root of 644430366 is about 863.7578330434.

The spelling of 644430366 in words is "six hundred forty-four million, four hundred thirty thousand, three hundred sixty-six".